THE ANALYSIS OF OVERPRESSURE CHARACTERISTIC IN MUTIARA FIELD, KUTAI BASIN, EAST KALIMANTAN

• Main Author: Aryo Seto, Reza
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/70395
• Institution: Institut Teknologi Bandung

The study area is located on the Mutiara Field, Lower Kutai Basin, East Kalimantan. The stratigraphy of the Mutiara Field consists of Balikpapan and Kampungbaru Group which are Middle Miocene to Pliocene in age. The purposes of this study are to determine top of overpressure, estimate pore pressure magnitude, analyze overpressure generating mechanism, and analyze the relationship between geological condition in study area and overpressure. The data processings were performed in fifteen wells (MUT-1, MUT-2, MUT-4, MUT-5, MUT-6, MUT-8, MUT-10, MUT-11, MUT-12, MUT-14, MUT-18, MUT-21, MUT-23, MUT-25, dan MUT-36) by using wireline log data, well report, temperature data, and pressure data. The geological condition of the study area is used as a reference to estimate pore pressure. The result of well data analysis shows that there are three pore pressure patterns in the study area, i. e. hydrostatic zone, non-loading overpressure zone, and minor process overpressure zone. Ten out of fifteen wells penetrate overpressure zone. The overpressure zone of Mutiara Field was encountered in the Balikpapan Group. The top of non-loading overpressure ranging 1897.7 – 2503.9 m with the magnitude of overpressure around 2795.7 – 6969.2 psi. Meanwhile, the overpressure with minor process is located at 1042.4 to 2054.35 m with magnitude ranging 1851.7 to 3571.7 psi. The temperature at top of non-loading overpressure is sufficient for clay mineral diagenesis, but further analysis is needed to explain what caused this type of overpressure. The vertical transfer of overpressure and hydrocarbon buoyancy are minor processes that caused this slight overpressure.